Inference system, inference method, and recording medium

Abstract

An inference method according to the present invention in an inference system inferring a probability that an ending state holds based on a starting state and a rule set, the method includes: when a rule set derived by excluding one rule from rules constituting a first rule set is set as a second rule set, a probability that the ending state holds based on the starting state and the first rule set is set as a first inference result, and a probability that the ending state holds based on the starting state and the second rule set is set as a second inference result, calculating an importance being an indicator indicating magnitude of a difference between the first inference result and the second inference result; and outputting the rule and the importance of the rule, being associated with each other for each of the excluded rule.

What is claimed is: 
     
       1. An inference basis presentation system presenting a basis inference inferring a probability that an ending state holds based on a starting state and a rule set, the inference basis presentation system comprising:
 a memory; and 
 at least one processor coupled to the memory, 
 the processor performing operations, the operations comprising: 
 acquiring a first rule set including a starting state, an ending state and at least one rule that is connected at least one of the starting state or the ending state from a device; 
 setting a rule set derived by excluding one rule from rules constituting the first rule set so as to have a probability different from a probability of the first rule set, as a second rule set, 
 setting a probability that the ending state holds based on the starting state and the first rule set, as a first inference result; 
 setting a probability that the ending state holds based on the starting state and the second rule set is set, as a second inference result; 
 for each of the excluded rule, calculating an importance being an indicator indicating magnitude of a difference between the first inference result and the second inference result; and 
 for each of the excluded rule, outputting the rule and the importance of the rule, being associated with each other to a device operated by a user. 
 
     
     
       2. The inference system according to  claim 1 , wherein
 the operations further comprises 
 outputting the rule with a higher value of the importance than the rule with a lower value of the importance preferentially. 
 
     
     
       3. The inference system according to  claim 1 , wherein
 the operations further comprises 
 outputting the rule, the importance of the rule, and a weight value previously calculated for the rule, being associated with one another. 
 
     
     
       4. The inference basis presentation system according to  claim 1 , wherein the operation further comprises:
 specifying a rule constituting the second rule by automatically computing an optimization problem, the optimization problem consisting of an objective function to minimize the number of the rule and constraints indicating the difference in probability for each of the subsets of rule. 
 
     
     
       5. The inference basis presentation system according to  claim 1 , wherein the operation further comprises:
 specifying a rule constituting the second rule by automatically computing an optimization problem, the optimization problem consisting of objective function to minimize difference in probability for each of the subsets of rules and constraints indicating a threshold the number of rules. 
 
     
     
       6. An inference basis presentation method in an inference system presenting a basis inference inferring a probability that an ending state holds based on a starting state and a rule set, the method comprising, by the inference system:
 acquiring a first rule set including a starting state, an ending state and at least one rule that is connected at least one of the starting state or the ending state from a device; 
 setting a rule set derived by excluding one rule from rules constituting the first rule set so as to have a probability different from a probability of the first rule set, as is set as a second rule set, 
 setting a probability that the ending state holds based on the starting state and the first rule set, as a first inference result; 
 setting a probability that the ending state holds based on the starting state and the second rule set is set as a second inference result, 
 for each of the excluded rule, calculating an importance being an indicator indicating magnitude of a difference between the first inference result and the second inference result; and, 
 for each of the excluded rule, outputting the rule and the importance of the rule, being associated with each other to a device operated by a user.